However, it is not as though God’s word has failed [coming to nothing]. For not all who are descended from Israel (Jacob) are [the true] Israel;

And Isaiah calls out concerning Israel: “Though the number of the sons of Israel be like the sand of the sea, it is only the remnant [a small believing minority] that will be saved [from God’s judgment];

It is as Isaiah foretold,

“If the Lord of Hosts had not left us seed [future generations from which a believing remnant of Israelites came],
We would have become like Sodom, and would have resembled Gomorrah [totally rejected and destroyed]!”

whereas Israel, [though always] pursuing the law of righteousness, did not succeed in fulfilling the law.

Brothers and sisters, my heart’s desire and my prayer to God for Israel is for their salvation.

But I say, did Israel fail to understand [that the gospel was to go also to the Gentiles]? First Moses says,

“I will make you jealous of those who are not a nation (Gentiles);
With a nation that lacks understanding I will make you angry.”

But of Israel he says, “All day long I have stretched out My hands [in compassion] to a disobedient and obstinate people.”

God has not rejected His [chosen] people whom He foreknew. Or do you not know what the Scripture says of Elijah, how he pleads with God against Israel?

What then? Israel failed to obtain what it was seeking [that is, God’s favor by obedience to the Law], but the elect [those chosen few] obtained it, while the rest of them became hardened and callously indifferent;

So I say, have they stumbled so as to fall [to spiritual ruin]? Certainly not! But by their transgression [their rejection of the Messiah] salvation has come to the Gentiles, to make Israel jealous [when they realize what they have forfeited].

Now if Israel’s transgression means riches for the world [at large] and their failure means riches for the Gentiles, how much more will their fulfillment and reinstatement be!

If the first portion [of dough offered as the first fruits] is holy, so is the whole batch; and if the root (Abraham, the patriarchs) is holy, so are the branches (the Israelites).

I do not want you, believers, to be unaware of this mystery [God’s previously hidden plan]—so that you will not be wise in your own opinion—that a partial hardening has [temporarily] happened to Israel [to last] until the full number of the Gentiles has come in;

and so [at that time] all Israel [that is, all Jews who have a personal faith in Jesus as Messiah] will be saved; just as it is written [in Scripture],

“The Deliverer (Messiah) will come from Zion,
He will remove ungodliness from Jacob.”